This invention relates generally to electrical connectors and more specifically to high current electrical connectors which use a resilient metal contact strip which provides a circumferential array of mechanically connected electrical contacts for transmitting large amounts of current from one cylindrical contact surface to another such as the inner surface of a barrel terminal to the outer surface of a pin terminal.
Electrical connectors of this type are already known from U.S. Pat. No. 3,453,587 granted to Rudolph Neidecker Jul. 1, 1969 which discloses an electrical connector which uses a metal strip 6 to transmit current from a jack or sleeve 1 or 1a to a mating plug 2. The metal strip 6 is slitted transversely at 7 to form a multiplicity of tongues 5 which incline at an angle of approximately 45 degrees at their central portions. The strip 6 is fitted into the sleeve 1 so as to be held by its own resilience against the inner periphery of the sleeve. With this arrangement the outer edges of the tongues 5 bear on the inner periphery of the sleeve 1 while the inner edges of the tongues 5 are positioned to engage the plug 2 when it is inserted into the sleeve. The tongues 5 twist resiliently when the plug 2 is inserted so that the inner and outer edges of the tongues 5 are biased into engagement with the respective peripheries of the plug and sleeve. A drawback of this electrical connector is that the high pressure, low contact area at the inner edges of the contact tongues 5 is sensitive to tolerance variation and subject to considerable wear after repeated disconnections and reconnections of the plug.
In the U.S. Pat. No. 4,039,238 granted to Glenn W. Johnson, Jr. et al Aug. 2, 1977 modifications for improving the electrical contact of the Neidecker contact strip with the plug or pin are proposed. More specifically, the Johnson et al connector uses an elongate contact strip 10 which has expanses 16 which are twisted about transverse axes 18 which are closer to one edge. Thus the inward finger parts 16a for engaging the pin 22 are longer and have a lower spring rate which reduces the sensitivity to tolerance variation according to the Johnson et al patent. This modification however does little if anything with respect to the problem of wear which occurs with repeated disconnections and reconnections of the pin 22.
In the U.S. Pat. No. 4,120,557 granted to Raymond G. Horrocks Oct. 17, 1978, a modification for improving field replacement of the electrical contact strip used in the Neidecker connector is proposed. More specifically, the electrical contact strip 10 of the Horrocks connector comprises a pair of closed annular rail portions 14 between which extend a cylindrical tubular array of louvers 16. Each louver has a bottom portion 18 with slanting portions 20 on each side. The slanting portions 20 are deflected upon engagement by one interconnection surface 28 or 30 which in turn forms protruding ridges 34 on the bottom portion 18 engaging the other interconnection surface. The contact strip 10 may be mounted in the bore of a housing with the portions 20 slanting inwardly as shown in FIGS. 8 and 9 or on a male plug with the portions 20 slanting outwardly as shown in FIG. 10. This modification likewise does little if anything with respect to the problem of wear because the edges of the slanting portions 20 engage the part which is repeatedly disconnected and reconnected. Moreover, this modification has considerable sensitivity to tolerance variation because the annular rail portions 14 are closed which also requires a two piece housing or male plug for assembly.